I have attached a draft of a schema I have been working on as an extension
to METS for use in encoding our descriptive metadata in the context of
METS:dmdSec.METS:mdWrap elements.  While I know this will not be of
universal interest, I would welcome comments and suggestions from anyone
with sufficient time and interest to give this a read--particularly since I
am still feeling my way with respect to the use of xml schemas.

I have tried to set the schema up so that the main gdm elements could be
use directly under a METS:mdWrap element, pretty much without restrictions,
or encapsulated, with more control, within a GDM:gdm element.  As currently
set up, the GDM:gdm element can contain a GDM:core element, which groups a
set of core, non-repeatable descriptive metadata elements.  The GDM:core
elements are currently governed by an <xsd:all>, which allows them to
appear in any order, but not to repeat.  The remaining, repeatable
descriptive metadata elements are governed by an <xsd:choice minOccurs="0"
maxOccurs="unbounded">, which allows them to repeat and to occur in any

With respect to attributes: in switching from the MOA2.DTD descriptive
metadata attributes to a XML Schema, I have tried to use more specific xsd
datatypes.  Thus the SEQ attribute that appears in many elements is now
defined as an "xsd:integer"; and PUBLIC as "xsd:boolean".

With respect to casing element and attribute names, I have tried to follow
the METS conventions.  Thus elements always begin with a lower case
letters; but new "words" within the element name begin with an upper case
letter.  Attribute names are all upper case.

I have also attached a very brief, example of a GDM encoding outside the
context of METS.

Rick Beaubien